Developed in the 1950's as a primary trainer for both the United States Navy and Air Force, the T-34 is used to instruct student pilots in basic flying skills. The original aircraft was designated as the T-34B and was used from 1955 to 1976. In 1978, the turboprop version of the T-34 entered service with the Navy. The T-34C is unpressurized, with a two seat stepped cockpit and and a single large turboprop engine, which, when combined with a light airframe produce flying qualities similar to, but safer than those of military jet aircraft. The Turbo Mentor is used by the Navy for primary flight training as well as intermediate flight training for those pilots destined for propeller driven fleet aircraft or helicopters. In addition, the Navy uses the T-34C for basic and intermediate Naval Flight Officer training, and the Airforce uses it for Navigator training.